Method for Manufacturing a Golf Club Head

ABSTRACT

A method for manufacturing a golf club head with an improved surface hardness and surface strength is disclosed. The method includes forging a spring steel to form a club head body with a striking faceplate portion and a back portion opposite to the striking faceplate portion, and quenching the club head body by a quenching medium at 800-1000° C.

CROSS REFERENCE TO RELATED APPLICATIONS

The application claims the benefit of Taiwan application serial No. 104120719, filed on Jun. 26, 2015, and the subject matter of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure generally relates to a method for manufacturing a golf club head and, more particularly, to a method for manufacturing a golf club head with an improved strength and hardness.

2. Description of the Related Art

A conventional method for manufacturing a golf club head includes forging a bar into a club head which has a striking faceplate. However, the surface strength and hardness of the golf club head, especially those of the striking faceplate portion, produced by the conventional method are not sufficient. The disadvantage is that the club head is apt to deform after hitting a golf ball many times, and the deformation of the club head can affect the hitting performance of the golf club head substantially.

Another conventional method for manufacturing a golf club head includes binding a club head body and a striking faceplate portion part by welding to obtain a conventional two-piece type club head before forming a club head body and a face portion part respectively. With the above method, the face portion part having high strength and hardness in the surface thereof can be used as a striking faceplate portion, thus the conventional two-piece type club head does not deform after hitting a golf ball many times. However, in comparison with the previously mentioned method, an additional welding process is needed. It increases not only the producing complexity of the conventional two-piece type club head, but also the production cost thereof. In light of this, an improvement in the conventional method for manufacturing a golf club head is necessary.

SUMMARY OF THE INVENTION

It is therefore the objective of this disclosure to provide a method for manufacturing a golf club head having high surface hardness and strength.

It is another objective of this disclosure to provide a method for manufacturing a golf club head with lower production complexity and cost while providing sufficient surface hardness and strength of the golf club head.

In an embodiment of the disclosure, the method for manufacturing a golf club head includes: forging a spring steel to form a club head body with a striking faceplate portion and a back portion opposite to the striking faceplate portion, and quenching the club head body by a quenching medium at a quenching temperature of 800-1000° C.

In a form shown, quenching the club head body includes quenching an entire area of the club head body.

In the form shown, quenching the club head body comprises soaking the entire area of the club head body in the quenching medium for 5-30 seconds.

In the form shown, quenching the club head body comprises quenching the striking faceplate portion of the club head body.

In the form shown, quenching the club head body comprises quenching the back portion of the club head body.

In the form shown, quenching the club head body comprises ejecting the quenching medium to the club head body with a nozzle head at a rate of 5-20 L/min.

In the form shown, the quenching medium is a fluid having a temperature of 5-40° C.

In the form shown, the method for manufacturing the golf club head further includes forming grooves on the striking faceplate portion of the club head body prior to quenching of the club head body.

In the form shown, forming the grooves comprises pressing the striking faceplate portion of the club head body to form the grooves.

In the form shown, the method for manufacturing the golf club head further includes forming grooves on the striking faceplate portion of the club head body after quenching of the club head body.

In the form shown, forming the grooves comprises milling the striking faceplate portion of the club head body to form the grooves.

In the form shown, the method for manufacturing the golf club head further includes preparing the spring steel made of 0.8-1.1 wt % of chromium, 0.65-0.95 wt % of manganese, 0.47-0.55 wt % of carbon, 0.15-0.35 wt % of silicon, 0.15-0.25 wt % of vanadium, less than 0.03 wt % of sulfur, less than 0.03 wt % of phosphor, less than 0.05 wt % of oxygen, 0.05 wt % of nitrogen, and a balanced amount of iron before forging the spring steel.

In the form shown, quenching the club head body results in a surface hardness of HV 267-700 of the club head body.

In the form shown, wherein quenching the club head body results in a tensile strength of 240-310 ksi of the club head body.

In the form shown, quenching the club head body results in a yield strength of 200-240 ksi of the club head body.

In the embodiment of the disclosure, the method for manufacturing a golf club head changes the crystalline phase of the club head body by quenching the club head body. Advantageously, the surface hardness and strength of the golf club head can be improved.

Due to the high surface hardness and strength of the golf club head, the golf club head produced by the method of the present disclosure can replace the conventional two-piece type club head. Meanwhile, in comparison with the conventional method for manufacturing a conventional two-piece type golf club head, the method of the present disclosure omits the welding process and reduces the production complexity and cost.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present disclosure, and wherein:

The sole figure shows the hardness distribution of the disclosed golf club head with regard to the depth.

DETAILED DESCRIPTION OF THE INVENTION

The method of the present disclosure for manufacturing a golf club head includes: a forging step and a quenching treatment step to form a golf club head, which can be used to hit a golf ball by a user.

In detail, the forging step is adapted to forge a spring steel to form a club head body. The club head body has the similar outline of a golf club head. Namely, the club head body may have a striking faceplate portion and a back portion opposite to the striking faceplate portion. After the subsequent quenching treatment step for the club head body to become the golf club head, the striking faceplate portion is, while hitting, the portion of the golf club head adapted to make contact with the golf ball. In addition, the club head body further includes a hosel connecting the striking faceplate portion and the back portion, which is adapted to connect with a shaft for a user to hold while hitting a ball. This can be understood by a person having the general knowledge in the art of the present disclosure and the detail is thus omitted.

For example, the spring steel may be selected from the SUP series of the spring steel material listed in Table 1. At the temperature of 800-1000 degrees centigrade, an upset forging, a mean forging and a fine forging are sequentially performed to get the club head body. With the temperature of the forging step higher than 800° C., the required forging pressure in the forging step is low. In addition, the temperature should not be higher than 1000° C. in the forging step. Specifically, the temperature higher than 1000° C. in the forging step may cause the problem of decarbonization in the spring steel. In the embodiment, for the purpose of illustration, the SUP 10 spring steel shown in Table 1 is selected, and the SUP 10 spring steel (including 0.8-1.1 wt % chromium(Cr), 0.65-0.95 wt % manganese(Mn), 0.47-0.55 wt % carbon(C), 0.15-0.35 wt % silicon(Si), 0.15-0.25 wt % vanadium(V), below 0.03 wt % sulfur(S), below 0.03 wt % phosphor(P), below 0.05 wt % oxygen(O), 0.05 wt % nitrogen(N), and the balance amount of iron(Fe)) including chromium and vanadium is forged at the high temperature of 800° C. Therefore, a golf club head having a higher surface hardness and surface strength is obtained after the quenching step.

Table 1 listing the compositions of the SUP series of the spring steel material is shown as the following.

C Si Mn P S Cr V Fe SUP3 0.75~0.90 0.15~0.35 0.30~0.60 0.035 ↓ 0.035 ↓ — — balance amount SUP6 0.56~0.64 1.50~1.80 0.70~1.00 0.035 ↓ 0.035 ↓ — — balance amount SUP7 0.56~0.64 1.80~2.20 0.70~1.00 0.035 ↓ 0.035 ↓ — — balance amount SUP9 0.52~0.60 0.15~0.35 0.65~0.95 0.035 ↓ 0.035 ↓ 0.65~0.95 — balance amount SUP10 0.47~0.55 0.15~0.35 0.65~0.95 0.035 ↓ 0.035 ↓ 0.80~1.10 0.15~0.25 balance amount

The quenching treatment step is a rapid cooling treatment to the club head body to change the crystalline phase of the club head body, so as to form the organization of Martensite phase. Therefore, the surface hardness and surface strength of the produced golf club head may be further improved. In the quenching treatment step, the temperature of the club head body may be maintained at a quenching temperature, then the quenching treatment is performed to the whole or a portion of the club head body with a quenching medium. For example, the quenching treatment may be performed to the whole club head body (however, it is preferred to exclude the hosel of the club head body), the striking faceplate portion of the club head body, or both of the striking faceplate portion and the back portion of the club head body. In this way, the surface hardness and surface strength of the golf club head may be improved.

For example, the quenching temperature may be 800-1000° C. as was used in the forging step. It means that the quenching treatment may be directly performed to the club head body with the quenching medium after the forging step. Alternatively, if the club head body has cooled down after the forging step, the club head body may be reheated to 800-1000° C. for performing the quenching treatment.

In addition, the quenching medium may be a fluid which has a relatively low temperature in comparison with the quenching temperature, such as water or oil of 5-40° C. For example, when the quenching treatment is performed to the whole club head body, it may be selected to soak the whole club head body (except for the hosel of the club head body) in the quenching medium for 5-30 seconds. It is preferred to soak the whole club head body in the quenching medium for 20 seconds. In this way, the anti-deformation ability of the produced golf club head is improved. As such, when a ball is hit by the golf club head, the ball will have a larger spin. When the quenching treatment is performed to a portion of the golf club head (i.e. the striking faceplate portion or both the striking faceplate portion and the back portion), the quenching medium is ejected to the club head body using a nozzle head (at an ejected amount of about 5-20 L/min, which makes the quenching treatment step able to provide a better rapid-cooling efficiency, with 12 L/min preferred). By the quenching treatment performed on the striking faceplate portion, the elastic deformation ability of the produced the golf club head is improved. By the quenching treatment performed on both the striking faceplate portion and the back portion, the golf club head which has a larger hardness in the front and back parts and a smaller hardness in the middle part is produced. As such, when a ball is hit by the golf club head, the ball will have a larger back spin.

By the said quenching treatment step, the surface hardness of the club head body may reach HV 267-700, the tensile strength of the club head body may reach 240-310 ksi, and the yield strength of the club head body may reach 200-240 ksi. Therefore, the golf club head with a high surface hardness and a high surface strength is finally obtained.

In addition, the method of the present disclosure for manufacturing a golf club head further includes a line-groove forming step which forms grooves on the striking faceplate portion of the club head body.

In the method for manufacturing a golf club head, the line-groove forming step may be performed before the quenching step and after the forging step. This means that the grooves are formed on the striking faceplate portion of the club head body after the club head body is formed by the forging step. At this moment, the grooves may be formed by the pressing method. Then, after the line-groove forming step, the club head body (for example, heating the club head body by a high-frequency magnetic wave) is reheated to perform the quenching step. In this embodiment, the grooves are formed under the pressure of 250-350 T for 1-5 sec. Then the club head body is hold and moved at a speed of 3-10 mm/s. After the high-frequency magnetic wave heating, the heating coils of the high-frequency magnetic wave are removed and then the quenching treatment step is performed.

Alternatively, in the method for manufacturing a golf club head, the forging step, the quenching treatment step, and the line-groove forming step may also be performed in order. In this moment, since the club head body has high surface strength and hardness after the quenching treatment, it is no longer appropriate to form the grooves with the aforementioned pressing method. Thus, the grooves may be formed on the striking faceplate portion of the club head body by taking some material off the club head body such as milling, etc.

To prove that the method for manufacturing a golf club head can produce the golf club head with the higher surface hardness and strength by the quenching treatment step, the following tests are performed as follows.

(A) Mechanical Properties

In this test, the SUP 10 spring steel material is selected as the spring steel. Respectively, the SUP 10 spring steel material is forged to form the club head body at the quenching temperature of 900-950° C. (Example A1) or 800-850° C. (Example B1). Then the quenching treatment is performed at the quenching temperature which is the same as the temperature of 900-950° C. (Example A1) or 800-850° C. (Example B1). Finally, the produced golf club heads are tested about the tensile strength, the yield strength and the hardness, and the test results are recorded in Table 2. In this test, the produced golf club heads (Examples A0 and B0) without performing the quenching treatment (i.e. cooling naturally at room temperature) are used as reference samples.

TABLE 2 Mechanical Properties of Examples of the Golf Club Head in this Test. Forging Quenching Tensile Yield Temperature Temperature Strength Strength Hardness Example (° C.) (° C.) (ksi) (ksi) (HV) A0 900~950 — 171.0 108.6 330 A1 900~950 900~950 297.6 211.6 520 B0 800~850 — 108.4 81.8 215 B1 800~850 800~850 247.2 228.4 490

Referring to Table 2, in comparison with Examples A0 and B0, Examples A1 and B1 which are treated by the quenching treatment show that the tensile strength, the yield strength and the hardness are effectively improved. Thus, the method for manufacturing a golf club head according to the present disclosure can improve the surface hardness and strength of the golf club head.

(B) Hardness Distribution

In this test, the golf club head produced by the method for manufacturing a golf club head according to the present disclosure is selected, and the depth hardness distribution thereof is measured. In the context, the depth in particular is referred to the depth measured from the surface (i.e. the surface of the striking faceplate portion that makes contact with a golf ball while hitting) of the golf club head.

Referring to the solo figure, the dash line represents the hardness of the club head body produced by the forging step and the hardness is about 215 HV. After the golf club head is treated by the quenching step, the hardness of the golf club head around the hitting surface may be improved by 1.8-2.75 times, and the depth of hardening is about 0.9 mm or less (as indicated by the solid line in the solo figure). Thus, the method for manufacturing a golf club head according to the present disclosure can improve the surface hardness and strength of the golf club head.

To sum up, the method for manufacturing a golf club head according to the present disclosure changes the crystalline phase of the club head body through the quenching treatment performed on the club head body. Advantageously, the surface hardness and strength of the produced golf club head is improved.

For the golf club head produced by the method for manufacturing a golf club head of the present disclosure, since the golf club head has high surface hardness and strength, the golf club head can replace the conventional two-piece type club head. Meanwhile, in comparison with the method for manufacturing the conventional two-piece type club head, the method for manufacturing a golf club head according to the present disclosure can omit the welding process, which reduces not only the production complexity but also the production cost.

Although the disclosure has been described in detail with reference to its presently preferable embodiments, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the disclosure, as set forth in the appended claims. 

What is claimed is:
 1. A method for manufacturing a golf club head, comprising: forging a spring steel to form a club head body having a striking faceplate portion and a back portion opposite to the striking faceplate portion, and quenching the club head body by a quenching medium at a quenching temperature of 800-1000° C.
 2. The method for manufacturing the golf club head as claimed in claim 1, wherein quenching the club head body comprises quenching an entire area of the club head body.
 3. The method for manufacturing the golf club head as claimed in claim 2, wherein quenching the club head body comprises soaking the entire area of the club head body in the quenching medium for 5-30 seconds.
 4. The method for manufacturing the golf club head as claimed in claim 1, wherein quenching the club head body comprises quenching the striking faceplate portion of the club head body.
 5. The method for manufacturing the golf club head as claimed in claim 4, wherein quenching the club head body comprises quenching the back portion of the club head body.
 6. The method for manufacturing the golf club head as claimed in claim 4, wherein quenching the club head body comprises ejecting the quenching medium to the club head body with a nozzle head at a rate of 5-20 L/min.
 7. The method for manufacturing the golf club head as claimed in claim 1, wherein the quenching medium is a fluid having a temperature of 5-40° C.
 8. The method for manufacturing the golf club head as claimed in claim 1, further comprising forming grooves on the striking faceplate portion of the club head body prior to quenching of the club head body.
 9. The method for manufacturing the golf club head as claimed in claim 8, wherein forming the grooves comprises pressing the striking faceplate portion of the club head body to form the grooves.
 10. The method for manufacturing the golf club head as claimed in claim 1, further comprising forming grooves on the striking faceplate portion of the club head body after quenching of the club head body.
 11. The method for manufacturing the golf club head as claimed in claim 10, wherein forming the grooves comprises milling the striking faceplate portion of the club head body to form the grooves.
 12. The method for manufacturing the golf club head as claimed in claim 1 further comprising: preparing the spring steel made of 0.8-1.1 wt % of chromium, 0.65-0.95 wt % of manganese, 0.47-0.55 wt % of carbon, 0.15-0.35 wt % of silicon, 0.15-0.25 wt % of vanadium, less than 0.03 wt % of sulfur, less than 0.03 wt % of phosphor, less than 0.05 wt % of oxygen, 0.05 wt % of nitrogen, and an balanced amount of iron before forging the spring steel.
 13. The method for manufacturing the golf club head as claimed in claim 1, wherein quenching the club head body results in a surface hardness of HV 267-700 of the club head body.
 14. The method for manufacturing the golf club head as claimed in claim 1, wherein quenching the club head body results in a tensile strength of 240-310 ksi of the club head body.
 15. The method for manufacturing the golf club head as claimed in claim 1, wherein quenching the club head body results in a yield strength of 200-240 ksi of the club head body. 